As the new Network for East–West Dialogue hosted further seminars in Warsaw and Budapest in 1987 and Prague in 1988, a historic upheaval was beginning in Eastern Europe. Barely within a year, the Communist regimes, losing confidence as Gorbachev's withdrawal of support became clear, fell one by one in the face of largely nonviolent revolutions emboldened by the same token. On 9 November 1989, the Berlin Wall was opened. The end of the Cold War, for which the peace movement had fought, was unfolding in front of its eyes. It was a momentous change, with huge ramifications for its future as well as that of Europe and the world.

Western leaders claimed that their 1979 decision had led to this outcome, but they had been forced to abandon it by Gorbachev's bold choices, which reflected the movement's pressure as well as his recognition of the USSR's fundamental weaknesses. After the Cold War ended, researchers discovered that the USSR, despite its monolithic façade, “was rife with debates about foreign policy” (Evangelista 1999: 6). The official peace committees had been listening to END and other Western activists, and much of Gorbachev's new international thinking, one Soviet insider argued, was “simply borrowed” from them (Burke 2017: 243).

In Eastern Europe, a “Helsinki effect” resulting from the 1975 Final Act, which made human rights part of a European settlement, meant that the Soviet leadership had to accept both international and domestic monitoring. But it had taken the activist “Helsinki network” across the bloc, with support from the Western peace movement, to ultimately force the pace, helping generate the mass democracy movements (Thomas 2001; Snyder 2011). NATO would later acknowledge the centrality to the change of the openings for civil society created by Helsinki (Shea 2009).

E. P. Thompson was therefore justified in claiming that END had “prefigured time and time again the events of 1989” (1991: 23). However, in many ways the denouement was unanticipated. He had argued that the Cold War was a self-perpetuating exterminist system that could only be broken from below, but the cycle of military competition had been interrupted from above. Thompson had presented Cold War rivalry as symmetrical, but asymmetry contributed greatly to how it ended.